A “travelator” is merely standard British English for the kind of moving walkway you find in the world’s airports, but here it lends an appropriately sci-fi ring to the idea, which has roots in the underground cities imagined by writers such as Isaac Asimov and H.G. Wells.

Notting Hill Gate Tube Station in London reimagined as an underground moving walkway.

Courtesy of NBBJ

Calling the concept “a radical rethinking of the London Underground’s Circle Line that promises to spur new ideas for urban mobility,” NBBJ explains in a press release that the Circle Line currently carries 114 million people annually along its 17 miles of track via eight trains that can reach a top speed of 20 miles per hour. One of the city’s most congested lines, it’s often subject to delays and “frequently unpleasant for overheated commuters.”

Diagram showing the varying speeds of each travelator in between station.

Courtesy of NBBJ

According to the proposal, commuters could jump onto the electronic circular route at a leisurely 3 mph, switching lanes in order to power themselves at up to 15 mph. “When added to an average walking pace of 3mph, pedestrians would actually move faster on foot than today’s Circle Line trains, which must stop for boarding at each station,” the designers write, resulting in a faster, more enjoyable and healthier journey.

London’s Circle Line was electrified 110 years ago this year. Opened in 1863, the London Underground is the oldest subway system in the world.

Courtesy of NBBJ

Kristin Hohenadel's writing on design has appeared in publications including the New York Times, Fast Company, Vogue, Elle Decor, Lonny, and Apartment Therapy.